Carboxyl group-containing polymers contained in carboxyl group-containing polymer compositions are useful polymers used in various industrial fields and are useful specifically for use in aqueous environment (e.g. dispersants, detergent compositions).
An example of conventional carboxyl group-containing polymers is a (meth)acrylic acid-based copolymer that includes 70 to 95 mol % of a structure unit (a) derived from a (meth)acrylic acid-based monomer (A) and 5 to 30 mol % of a structure unit (b1) derived from a (meth)allyl ether monomer (B1) and is terminated with a sulfonic acid group at one or both ends of its main chain (Patent Literature 1). Patent Literature 1 states that this (meth)acrylic acid-based copolymer exhibits excellent chelating ability, dispersibility, and gel resistance.
Another example is a scale inhibitor that contains a (meth)acrylic acid-based polymer including a structure unit (a) derived from a (meth)acrylic acid-based monomer (A), a structure unit (b) derived from a sulfonic acid-based monomer (B), and a structure unit (c) derived from another (meth)acrylic acid-based monomer (C) (Patent Literature 2). Patent Literature 2 states that this scale inhibitor containing a (meth)acrylic acid-based polymer has an excellent capacity to inhibit scale of calcium phosphate.